1. Field of the Invention
The invention relates to a method for adjusting a scanning module, and more particularly to a method for adjusting and mounting a scanning module with the aid of a temporary fixing force.
2. Description of the Related Art
A scanning module is mainly applied to an image acquisition device, such as a scanner, a fax machine, a multi-function peripheral, or the like. The scanning module converts an image of a document into an electric signal, and thus usually includes an image sensor, such as a charge coupled device (CCD) image sensor. When the CCD image sensor is used, a lens and several reflecting mirrors are usually needed. The reflecting mirrors reflect an optical signal of the document to the lens, which focuses the optical signal onto the image sensor, which converts the optical signal into the electric signal.
In order to ensure the stable quality of the optical signal received by the image sensor, the scanning module has to be adjusted in the assembling processes. The adjusting method mainly includes the steps of adjusting the positions of the lens and the image sensor.
When the position of the image sensor is adjusted, a circuit board, on which the image sensor is attached, is screwed to the base of the scanning module by two screws in the prior art method. After the screwing process for the circuit board is finished, the adjuster tests the image quality. If the image quality is not above satisfactory in accordance with the standard measurements, the adjuster may slightly unscrew one or two of the screws and then move the circuit board. Next, the adjuster screws the circuit board to the base of the scanning module, and then tests the image quality. Such operations are repeated until the acceptable image quality is obtained.
Although the adjuster may monitor the image quality while unscrewing the screw and moving the circuit board so as to adjust the position of the loosened image sensor to an acceptable position, the position of the image sensor may slightly fluctuate after the screw is screwed tightly, and the image quality will be influenced again. Consequently, the conventional adjusting method has to be performed with the aid of considerable experiences, and it takes a long time to unscrew and screw the screw for the adjustment so as to obtain the optimum corresponding state between the image sensor and the lens.